Heretofore it was difficult to form airfoil parts, such as a blade, a vane, or the like, for use in a jet engine or turbine or similar structure where deformations in the airfoil part existed in non-parallel planes at different angles to the general plane of the airfoil parts. Such vanes or blades could not be made using the usual equipment of upper and lower horizontal platens and wherein all posts or recesses had to have parallel surfaces normal to the platens. If undercut surfaces were designed extending in different planes at an angle to each other, usually extra removable mold pieces had to be provided which called for partial assembly and disassembly of the mold each time a piece was cast.
The object of the present invention is to provide a mold structure for forming an airfoil part such as a blade, a vane, or the like, having shapes heretofore difficult to cast. The structure disclosed herein includes upper and lower mold portions, completely enclosing a generally horizontal chamber of the shape complementary to a core for the airfoil part, each portion carrying a plurality of blocks, of which each has a partial core-forming surface presented inwardly and each partial core-forming surface including formations turned at approximately 90.degree. to that partial surface complementary to airfoil part passage deformations to be formed which extend at different non-parallel angles between different blocks. These blocks in the present invention are mounted in the upper and lower mold portions on opposite sides of the chamber for forming the airfoil part core and so mounted that each block is withdrawable in a direction normal to the associated airfoil core partial surface.
The accompanying description discloses specific structures for withdrawing the blocks in different directions, at angles to each other, depending upon the structure to be formed.
The structure defined herein in detail involves a negative embodiment of the core structure, wherein a pattern is first formed having certain solid and open portions which, by investment casting, reverses the solid and open parts to provide the desired core which is embodied in a blade or vane. In a later portion of the specification, the changes necessary in the described structure herein will be indicated in order to form a positive embodiment of the core structure which may be directly assembled into the finished blade or vane.